The foreseen trigger rate of 10 events/sec allows 10 sec readout time per event. In addition, with the beam specifications proposed (5 10 ptc/sec spread over a 1 cm area), we expect a rather low occupancy.
The time needed to readout a full chip (according to the RD20 design) is of 4, 8 or 16 sec with the clock of 40, 20 or 10 MHz respectively.
Consequently 40 MHz and 20 MHz readout frequencies will not cause any dead time. But using 10 MHz clock would make us loose all features of the RD20 chip and cause 16 sec dead time.
A possible solution would be to use 20 MHz clock and 100 nsec peaking time. The use of a deconvolution algorithm would guarantee a time resolution of 50 nsec . In this situation we would have 2-3 beam particles recorded per event and a double interaction recorded in 5% of the cases.